Top 4 most popular carburetors

Quick comparison: the top 4 Puch carburetors

Use this table as a starting point. The correct carburetor still depends on your exact cylinder, exhaust, intake, air filter, ignition timing and riding style.

Why carburetor choice matters on a Puch

A cylinder and exhaust are important, but the carburetor is one of the parts that has to be adjusted correctly. The carburetor controls how much fuel and air the engine receives. If the size or jetting is wrong, the engine can run poorly even when the rest of the setup is good.

The common mistake is fitting a large carburetor because it looks faster. A 21mm carburetor on a normal 70cc cylinder can be difficult to tune and may perform worse than a smaller carburetor that actually matches the engine. Start with the setup, not the number stamped on the carburetor.

#1: Replica Bing 15mm - the best everyday choice

The 15mm Bing replica is the number one seller and the carburetor that makes sense for the largest group of Puch riders. It is simple, parts are available, and it works well on many standard or mildly tuned engines.

For a standard 50cc setup, a 15mm Bing can already be an improvement if the intake is not restricted. For a 70cc street setup, it is often a very practical choice when you want more power without turning the bike into a high-consumption race setup.

A big advantage is fuel consumption. Bigger carburetors can use noticeably more fuel, especially when you ride to school, work or around town. A correctly jetted 15mm Bing keeps the setup usable for normal riding.

• Best for standard 50cc and mild 70cc street setups.
• Simple tuning: mainly main jet and needle adjustment.
• Works well with the original-style air filter when the restriction is removed.
• Repair and replacement parts are easy to keep in stock.
• Always check whether your carburetor uses 3.5mm or 4mm jets before ordering jets.

Need parts for a Bing-style setup? View the Puch Bing parts category.

#2: Replica Dellorto PHBG 17.5mm - the sensible tuning step

The 17.5mm PHBG-style replica is a popular step up when a 15mm carburetor is no longer enough. It is often included in tuning sets with a cylinder, exhaust and jets, and it also sells well as a separate carburetor.

A 17.5mm carburetor is a good maximum size for many 50cc and 70cc intake setups. In many cases it fits the intended manifold size without needing extreme intake work. If you go larger, you may need to widen or rework the intake and make sure the rest of the setup can actually use the extra flow.

The replica PHBG can be slightly trickier to adjust than a simple Bing, but it works very well when it is set up properly.

• Good choice for stronger 50cc and 70cc tuning setups.
• Useful when you want more adjustment range than a basic Bing setup.
• Usually requires careful main jet and mixture screw setup.
• A 70cc PSR or Airsal-style setup often ends up around a 76 or 78 main jet, but this is only a starting reference and not a guaranteed setting.

For replacement parts and tuning parts, view the Dellorto PHBG / SHA parts category.

#3: Dellorto PHBG 21mm - proven for serious setups

The Dellorto PHBG 21mm is a proven carburetor for serious Puch tuning. It has been used for many years, parts are widely available, and it gives plenty of tuning options through jets, needles and other PHBG parts.

This is not the carburetor to choose just because you want a bigger number. A 21mm PHBG belongs on a heavily tuned 70cc, a milled cylinder, a Gilardoni-style setup or another engine where the intake, exhaust and ignition are prepared to match it.

One useful air filter detail: with the right adapter ring, the air filter connection can go from 32mm to 35mm, which opens up more air filter options such as TwinAir-style filters.

• Best for tuned and milled cylinders that can actually use a 21mm carburetor.
• A strong option for Gilardoni-style setups where proven PHBG tuning is useful.
• Available in clamp and rubber-mounted versions depending on the manifold setup.
• Use the correct air filter adapter if your chosen filter does not match the carburetor connection.

Make sure the carburetor, manifold and air filter match before building the setup.

#4: Polini CP 21mm - modern, light and high quality

The Polini CP 21mm is the modern option in the top four. It has a high-quality finish, a light body, a chrome-plated throttle slide and good tuning parts availability. It was designed with scooter-style applications in mind, but it can work very well on the right Puch setup.

The key phrase is: the right setup. The Polini CP 21mm is normally used on 74cc or heavily reworked 70cc engines. It is not the best choice for a normal street Puch or a basic 50cc/70cc cylinder.

The Polini CP can take more work to tune on some Gilardoni setups. In those cases, a Dellorto PHBG may be the easier and more predictable option.

• Best for 74cc, reworked 70cc and race-style engines.
• Modern design with good tuning part support.
• Includes capped oil-mixing ports that are not used on normal premix Puch setups.
• Not recommended as a simple bolt-on upgrade for a basic street engine.

Looking for tuning parts? View the Polini CP / PWK parts category.

Clamp mount vs rubber mount: what is the difference?

Many Dellorto and Polini carburetors are available as clamp versions or rubber-mounted versions. A clamp version is often easier to install because it clamps directly to the manifold. A rubber-mounted version uses a rubber adapter and hose clamps.

Rubber mounting has two big advantages. First, it reduces vibration, which helps prevent the fuel from foaming in the carburetor. Second, it reduces heat transfer from the hot cylinder and manifold into the carburetor. Less heat is generally better for a two-stroke setup, especially on a race or high-performance engine.

Basic tuning tips before your first ride

No carburetor is plug-and-play for every Puch. The same carburetor can need a different jet on a different cylinder, exhaust, air filter or ignition setup. Always tune safely before riding hard.

Start rich enough to avoid damage, then work toward the correct main jet. Check throttle response, engine temperature, plug color and how the engine behaves at full throttle and part throttle. If the engine four-strokes heavily, bogs, overheats or will not respond to mixture screw changes, stop and correct the setup.

You can also browse the full Puch carburetor parts category to compare carburetors, jets, manifolds and air filter parts.

FAQ: Choosing a Puch carburetor